Method for producing accurate type



0a. 24, 1967 P. J. THUT 3,348,404

METHOD FOR PRODUCING ACCURATE TYPE Filed Dec. 24, 1964 3 Sheets-Sheet 1 INVENTOR PAUL J. THUT Oct. 24, 1967 p J THUT METHOD FOR PRODUCING ACCURATE TYPE 3 Sheets-Sheet 2 Filed Dec. 24, 1964 STEP WIDTH OF TYPE MEMBER F|G.4b

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Fl G 2b INVENTOR PAUL J. THUT I I I LINE WIDTH Mill |l Illlllll $654 32 1 ol PLUSTAPS' MINUSTAPS Oct. 24, 1967 P. J. THUT 3,348,404

' METHOD FOR PRODUCING ACCURATE TYPE Filed Dec. 24, 1964 3 Sheets-Sheet 5 FIG.5 O

INVENTOR PAUL J. TH UT United States Patent 3,348,404 METHGD FOR PRODUCING ACCURATE TYPE Paul J. Thut, Penfield, N.Y., assiguor to Burroughs Corporation, Detroit, Mich., a corporation of Michigan Filed Dec. 24, 1964, Ser. No. 421,044 5 Claims. (Cl. 72-340) ABSTRACT OF THE DISCLOSURE It is known in the art to produce print wheels by a swaging or knurling process wherein an engraved matrix is rolled in pressure contact with a type member blank.

During the swaging or knurling operation, the material of the type member blank is caused to flow into the intagliated characters of the matrix thereby forming raised type on the print member. The blank, for example, may be uuhardened tool steel in the shape of bar, disc, or wheel.

In producing type wheels by the swaging or pressure rolling methods, great care must be taken to insure that the type wheel is synchronously rotated in contact with the intagliated matrix to prevent marn'ng of the raised accurate type. Further problems arise because of the generous angle which must be included on the sides of the intagliated characters of the master wheel to allow the raised type to roll clear from the die without distorting or marring the surface of the type. This angle often results in variations in line widths of the characters especially when subsequent face finishing operations are performed. In prior art methods producing type members by the above methods, it has been common practice to grind the type member after the swaging operation to remove surface metal from the rim which is expressed during the swaging operation. The grinding operations of the prior art were primarily directed to obtaining true type members and were not directed to obtaining characters having accurate line width dimensions.

Recent advances in the art of mechanically handling written documents and articles have accentuated the problems encountered in the economic manufacture of extremely accurate type. One system for reading characters by machine which permits a greatly increased processing speed in document handling is the magnetic ink recognition system. One application of this type of printed document processing arises in the mechanization of banking problems. The use of checks in personal and business transactions has expanded enormously in the last decade and therefore machines have been built which can be called upon to process upwards of 175,000 checks dailv.

The Oflice Equipment Manufacturers Institute and the American Bankers Association, after some preliminary studies, recommended magnetic character recognition for use in banking practice. The standard characters of the MICR system comprise ten digital digits and four coding symbols, each designed to be sufiiciently different for machine recognition while still retaining suificient detail of their orthodox counterparts to enable visual recognition. The characters are printed on the documents to be processed with magnetic ink of controlled density and are subsequently magnetized. The flux lines of the magnetized ink induce signals in a read head as the document passes a sensing station and the signal obtained is a function of the time rate of change of the flux linkages.

Each of the ten digits and four coding symbols utilized in MICR systems has its own nominal read-back voltage waveform and it is necessary to employ logical circuitry to identify these waveforms with the accuracy de manded by banking practice. Recognition is complicated by the fact that since the check or other item contains many digit characters, one waveform is usually closely followed by another as the documents are rapidly processed through, for example, a check sorter.

In one particular application of the magnetic ink character recognition system, three features of a read-back voltage waveform are utilized to identify a character as it passes the sensing station, namely: the position of the peaks in the character waveform, the polarity of the signal at various positions Within the character and, fi

nally, the relative amplitudes of the peaks at these positions. These features of the characteristic waveform for each character and coding symbol are a function of the line width of the characters and the scanning rate. For a more complete understanding of the graphic character recognition system utilizable in, for example, the MICR System, reference may be had to Patent No. 3,103,646, issued Sept. 10, 1963 to I. M. Sheaifer, Jr. et al., and Patent No. 3,096,506, issued July 2, l963 to Choa Kong Chou et al., which are assigned to the assignee of the present invention.

The production of print Wheels having characters which have line width tolerances within the strict specification required for machine reading has not heretofore been economically feasible with the normal swaging or pressure rolling operations. The pressure rolling and swaging techniques have been prohibitively expensive primarily because the costly intagliated matrix die could heretofore be utilized to produce only a relatively few print wheels before the marring and wear of the die due to the pressure rolling necessitated replacement if accurate type was to be produced.

Applicants present invention has obviated these problems encountered in the prior art and has made possible the successful production of print wheels having accurate type thereon in an economical manner by employing an intagliated matrix having oversized characters therein and subsequently shaving the raised character outlines of the print wheel after the swaging or pressure rolling operation.

Briefly stated, applicants process for producing accurate type comprises the steps of producing slightly oversized relief characters on a type blank member by bringing the blank into pressure contact with a master die having oversized intagliated type engraved therein whereby material of the blank flows into and fills the intagliated type of the master die, shaving the outline of the raised characters to predetermined line Widths respectively uniform as to each line width throughout the shaved depth of the character, hardening of the type faces and subsequently grinding the hardened type faces to the desired finish.

Accordingly, it is the principal object of this invention to provide an improved method for producing accurate type on the periphery of a type wheel.

Another object is to provide an improved method for economically producing relief type characters having uniform line Width specifications.

Another object is to enable more economic manufacture of accurately formed raised type.

The above features and objects, and other desirable features of the disclosed method may best be understood by reference to the following detailed description in connection with the following figures in which:

FIG. 1 illustrates a mechanism for producing raised type by rolling an intagliated master wheel in pressure contact with a type wheel blank.

FIGS. 2a, 2b, and 2c illustrate selected digits of the MICR system and their associated voltage time waveforms. 7

FIG. 3 is an isometric drawing of the MICR character zero produced on a rectangular type blank in accordance with applicants invention.

FIGS. 40, 4b, and 4cshow a flow diagram graphically illustrating the sequential steps as seen along line AA of FIG. 3 of applicants method for producing accurate raised type.

FIG. 5 illustrates a method for simultaneously shaving a plurality of raised character outlines on a type wheel in accordance with the principle of applicants invention.

Referring now to FIG. 1, a plan view of suitable apparatus including fragmented elements of a lathe for producing raised type on a type wheel blank by rotating the blank in pressure contact with a master matrix wheel is shown. The type wheel blank 11 is shown mounted on an arbor 15 by means of clamping rings 13 and 13'. Gear 17 is likewise supported on arbor 15 and nut 19 securely fastens the clamping rings and the type wheel blank therebetween in fixed relationship. Intagliated master wheel 21 is shown in pressure contact with type wheel blank 11.

The matrix Wheel 21 is mounted by means of bearings and 25' on an arbor not shown, and gear 23 is likewise supported on the arbor not shown, mounted on bearings 25 and 25.

During the formation of the type the type wheel blank 11 is adapted to be rotated by means of a lathe in pressure contact with the intagliated matrix Wheel 21. The lathe, as shown in fragmented form in FIG. 1, comprises a head stock spindle 27 having mounted thereon a face plate 29, a line center 31, a fragmented tail stock spindle 33, dead center 35, the cross slide 37, cross slideways 39, cross slide screw 41, and the cross slide handle 43. A lathe dog clamped to arbor 15 serves to drive the arbor from the face plate 29. A hole, not shown, having been previously located in the desired angular relationship with a point in the periphery of the type wheel, may be utilized to accurately mount the type wheel blank on arbor 15. The gears 17 and 23 are meshed according to markings not shown provided thereon to insure the proper align ment of the type wheel blank 11 and matrix wheel 21. Pressure is applied by turning the handle 43 thereby forcing the cross slide toward the center of the lathe and the matrix wheel 21 against the periphery of type wheel blank 11. When the cross slide has encountered the stop, the lathe is allowed to turn for a short period to insure the even flow of the metal of the type wheel 11 into the intagliated characters provided in the periphery of the matrix wheel.

Referring now to FIGS. 20, 2b, and 2c, there are shown schematic diagrams of characters 0, 2, and 4 of the MICR system and their characteristic waveforms generated when a document bearing the respective indicia passes an appropriate reading station. Directly below the numeral 0 designated 51 there is shown a waveform 57 which represents the induced voltage in a read-head winding. The waveform 57 is superimposed on a delay line 59 which has plus taps and minus taps thereon. Further in FIGS. 21) and 2c, the printed MICR numerals 2 and 4 are designated 53 and 55, respectively, with their respective voltage output waveforms 61 and 63. It is to be understood that the printed figures such as the numerals 0, 2, and 4 of FIGS. 2a, 2b, and 2c are scanned as shown by the arrow from right to left, that is, the documents transported under the read-head moving from left to right so that the right-hand edge of the numeral is scanned first. This is more clearly depicted by the direction of time t indicated in conjunction with the voltage waveforms.

As hereinbefore stated, each of the ten digits and the four coding symbols of the MICR system has its own nominal read-back voltage waveform and the problem then arises to identify each waveform, Variations in the nominal characteristic waveform, because of disturbances such as malformation of the magnetic characters or distortions in the magnetization of the magnetic characters, would result in erroneous operation of the machine reading device. The three features of the read-back voltage Waveform which are utilized to identify a printed character are the position of the peaks in the character waveform, the polarity of the signal at various positions within the characters and'therelative amplitudes of the peaks at these positions. Therefore, to insure accurate, dependable operation of the machine reading device utilizing the magnetic ink character recognition system, it is desirable to have uniform type to produce document to be processed by such machines so that the nominal character waveforms will be as nearly identical as possible thereby minimizing the possibility of error.

Referring'now to FIG. 3, there is shown an isomeric view of the MICR character 0 produced on a rectangular type blank in accordance with applicants inven tion. The rectangular type blank member 69 has an essentially planar type surface 71 and the MICR character 0 designated 73 formed thereon. Considering FIG. 3 in conjunction with FIGS. 4a, 4b, and 4c, the first step in practicing applicants invention comprises the production of raised type on planar surface 71 to a rolled height 75. As shown in Step A of FIGS. 4a, 4b, and 4c, the sides of raised type 75 form an angle a with the normal to the surface 71. This angle being in the order of 14 is required to allow the raised type to roll clear of the matrix die without distorting or marring the type. The second step of applicants process comprises the shaving of the outline of the raised type to the desired line width 77 and depth 79 thereby producing type having essentially planar sides, orthogonal to the surface 71 and type face 81.

As illustrated in FIGS. 2a, 2b, and 2c, all MICR characters do not necessarily have a uniform line width throughout all line segments of the character. Generally in practicing applicants invention, the outline of a raised character is shaved to predetermined line Widths respectively uniform as to each line width throughout the shaved depth. In the case of a type wheel, the finished surface of the type is preferably in a plane substantially parallel to the major axis of the wheel. Therefore, if the sides are cut or shaved substantially orthogonal to the plane of the finished type face, then depth variations in the finishing operation will not result in line width variations. Thus in either embodiment cross sections cut through the shaved outline of the raised character will result in substantially constant cross sectional areas.

In practicing applicants invention, accurate type within the tolerance specification of the MICR system has been obtained by employing an intagliated master die with a type face width being 1 or 2 mils oversized around the complete character outline. As shown in Step B of FIG. 412, by employing an accurately engraved punch the initially oversized character outlinemay be shaved to the desired line width. Subsequent to the shaving operation, as shown in Step C of FIG. 40, the raised type, after halilrdening operation, may be ground to the desired Referring now to FIG. 5, there is illustrated a method for simultaneously shaving a plurality of raised oversized characters on the periphery of a type wheel in a single operation. The shaving fixture comprises a plurality of reciprocable punches 87-0 through 8744, radially positioned about a shaft 89 which is adapted to support a type Wheel 91 having oversized characters on its periphery. An appropriate mark on shaft 89, not shown, may be utilized to accurately position the type wheel in relation to the reciprocable punches. Thereafter the reciprocable punches having accurately engraved characters in the end proximate the type wheel may be cycled thereby simultaneously shaving outlines of the characters on the periphery of the wheel to form the finished print wheel. In the preferred embodiment of the shaving fixture, the sides of the accurately sized characters engraved in the punches are substantially parallel to the line of motion of the radially disposed reciprocable punches. As would be evident to those skilled in the art, a plurality of print wheels may be aligned on a common shaft and simultaneously shaved by employing a like plurality of shaving fixtures similar to shaving fixture 85. In either embodiment the type wheels are preferably accurately indexed to precisely align the shaving fixture and the type wheel prior to the shaving operation so that the finished characters are properly positioned with respect to a predetermined reference point on the periphery of the type wheel. Further, while it would be possible to individually cycle each reciprocable punch to shave the outline of each character, it is preferable, in order to prevent the deformation of the print wheel during the shaving operation, i.e., to prevent the reciprocable punches from warping the type wheel outof-round, that the reciprocable punches of shaving fixture 85 be simultaneously cycled wit-h substantially equal pressure being applied to each punch.

The foregoing drawings and description are to be understood as exemplary only and are not intended in any way to limit the scope of applicants invention which is I set forth in the appended claims.

I claim:

1. The method of forming accurate raised type on a periphery of a type wheel comprising the steps of making a relatively hard master wheel having oversized intagliated characters therein,

synchronously rotating said master wheel in pressure contact with a relatively soft type wheel blank whereby metal of the type wheel flows into and fills the intagliated characters of the master wheel thereby forming raised characters on the periphery of the type wheel, and

vertically shaving the outlines of the raised characters to predetermined line widths respectively uniform as to each line width throughout the shaved depth of the character.

2. The method of forming accurate raised type on the periphery of a type wheel wherein the faces of the finished type individually lie in planes substantially parallel to the major axis of the Wheel comprising the steps of synchronously rotating a relatively hard master wheel having intagliated type engraved therein in pressure contact with a relatively soft type wheel blank Whereupon material of the type Wheel flows into and fills the intaglio type of the master wheel thereby forming oversized raised characters on the periphery of the type Wheel,

driving a plurality of punches each having an accurately sized engraved character therein into contact with each corresponding oversized character whereby the outline of each raised character is shaved to the desired line width having sides substantially perpendicular to the plane of said finished type, and grinding the type faces to the desired finish. 3. The method of forming an accurate raised type on the periphery of a type wheel comprising the steps of synchronously rotating a relatively hard master wheel having intagliated type engraved therein in pressure contact with a relatively soft type wheel blank whereupon material of the type wheel flows into and fills the intaglio type of the master wheel thereby forming oversized raised characters on the periphery of the wheel, mounting the type wheel in a shaving fixture having a plurality of reciprocable punches radially disposed about the periphery of said wheel wherein each punch has an accurately sized engraved character therein, each of said accurately engraved characters having sides substantially parallel to the line of motion of said punches, respectively, aligning the type wheel with characters on the periphery thereof juxtaposed with corresponding characters engraved in the punches, and simultaneously cycling the punches to trim the individual character outlines to predetermine line widths. 4. The method of producing accurate type comprising the steps of producing a slightly oversized relief character on a type blank member by bringing the blank into pressure contact with a master die having an oversized intagliated character engraved therein whereby metal of the blank flows into and fills the intagliated character of the master die, and shaving the outline of the oversized raised character to a predetermined character Wall thickness whereby cross sectional areas through the shaved portion of the raised character are substantially constant. 5. The method of claim 4 additionally including the steps of hardening the type face, and

grinding the hardened type face to the desired finish.

References Cited UNITED STATES PATENTS 3,177,104 4/1966 Miller 72-80 CHARLES W. LANHAM, Primary Examiner. L. A. LARSON, Assistant Examiner. 

1. THE METHOD OF FORMING ACCURATE RAISED TYPE ON A PERIPHERY OF A TYPE WHEEL COMPRISING THE STEPS OF MAKING A RELATIVELY HARD MASTER WHEEL HAVING OVERSIZED INTAGLIATED CHARACTERS THEREIN, SYNCHRONOUSLY ROTATING SAID MASTER WHEEL IN PRESSURE CONTACT WITH A RELATIVELY SOFT TYPE WHEEL BLANK WHEREBY METAL OF THE TYPE WHEEL FLOWS INTO AND FILLS THE INTAGLIATED CHARACTERS OF THE MASTER WHEEL THEREBY FORMING RAISED CHARACTERS ON THE PERIPHERY OF THE TYPE WHEEL, AND VERTICALLY SHAVING THE OUTLINES OF THE RAISED CHARACTERS TO PREDETERMINED LINE WIDTHS RESPECTIVELY UNIFORM AS TO EACH LINE WIDTH THROUGHOUT THE SHAVED DEPTH OF THE CHARACTER. 